Neurológia pre prax 6/2014

Myasthenia gravis and woman: pregnancy, delivery, postpartum period and transient neonatal myasthenia

Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction. MG often affects women in the second and third decades of life, overlapping the childbearing years. Women with MG should not be discouraged from conceiving, however, they should discuss their plan for pregnancy with their neurologist and their gynecologist. Generally is accepted that MG females who wish to become pregnant should have their MG under good control, either in remission or in significantly improved and stable condition. MG can be well managed during pregnancy with safe and effective therapies. Anticholinesterase drugs are the mainstay of the treatment. When MG symptoms are not satisfactorily controlled, corticosteroids and azathioprine can be used. Regarding potential adverse effects on the fetus and newborn, pregnancy should be avoided in women treated with cyclophosphamide, mycophenolate mofetil, cyclosporin and methotrexat. MG exacerbations in pregnancy are not frequent and usually mild, they may occur especially in the first trimester. Great significance is attached to the mode of delivery since it is still widely accepted that patients with MG have to deliver per elective cesarean sections. In women being in long-term remission spontaneous vaginal delivery should be the aim. In the postpartum period MG symptoms may worsen and the increased risk of exacerbation is present mainly in cases where the disease is not stable before conception. All infants born to myasthenic mothers should be carefully observed for the presence of transient neonatal myasthenia which occurs in 4 to 12% of infants of mothers with MG. Infants of women with MG do have also an increased risk of developing arthrogryposis multiplex congenita. This is thought to be caused by maternal antibodies crossing the placenta and blocking the function of fetal isoform of acetylcholine receptor, leading to fetal paralysis. Successful management of women with MG during pregnancy, delivery and puerperium, including their infants, requires close cooperation between a neurologist, an obstetrician, a neonatologist and a well-informed patient.

Keywords: myasthenia gravis, women in childbearing years, pregnancy, delivery, postpartum period, transient neonatal myasthenia gravis, arthrogryposis multiplex congenital, multidisciplinary management.